1. Field of the Invention
The present invention relates to a vehicle headlight with a dish-shaped reflector, where the inner reflection surface has in its sections containing the dish-axis in each case an ellipse segment, where the eccentricity of the ellipse increases when going from the vertical axial section to the horizontal axial section.
2. Brief Description of the Background of the Invention Including Prior Art
Dish-shaped reflectors where sections containing the dish axis show ellipse segments for the inner curve of the reflector surface section are employed in headlights, which operate according to the projector principle. Such a headlight is described in German Patent Application Laid Open DE-OS No. 2,446,521.
A reflector is employed where the reflection surface in a vertical axial section represents an ellipse segment, where the inner focal point is designated as F and where the diaphragm designated as a screen is disposed at its outer focal point. The outer focal point of this ellipse segment forms at the same time the focal plane of the lens body disposed in front of the reflector. The reflection surface shows in the horizontal axial section a different form, which can among other shapes also be provided as elliptical. The description teaches about this only that this other shape or also elliptical shape is provided such that the light reflected by the reflector is scattered more in the horizontal directions as compared to the vertical directions. FIG. 3 of DE-OS No. 2,446,521 indicates that the ellipse running in a horizontal longitudinal section through the reflector is disposed such that its longer axis a' is vertical on the axis a in the horizontal axial section through the reflector. An ellipse segment with two focal points results from the horizontal axial section, which focal points are disposed on the front straight delineating line of this ellipse segment. The sections through the reflector between the horizontal axial section and the vertical axial section are to be provided such that the reflector as seen from the front again provides an ellipse according to FIG. 2, and that all sections, which are parallel to the section, as shown in FIG. 2, again result in ellipses.
The light is in fact strongly bundled in the vertical direction of such a headlight and is scattered more in horizontal direction, however the scattering in horizontal direction is uncontrolled and very heavy, since the incandescent filament is disposed between the two focal points of the ellipse resulting in the horizontal axial section.
It is a further disadvantage of conventional reflectors that the outer front edge of the reflecting dish runs in a plane. This means that the largest possible reflection surface is not exploited without that in the main output direction, which is at the same time the removal direction from the mold tool of the reflector produced by injection molding or casting, an undercutting or back taper results.